1. Field of the Invention
This invention relates to a method for folding an electronic device with a flexible display where the device case hinges such that the display experiences neither a tension nor compression force when the device is folded.
2. Statement of the Problem
It is convenient to be able to fold a mobile electronic device. Folding a tablet sized device, for example, would allow it to fit in a user's pocket. Folding displays are becoming possible with the advent of OLED displays processed on thin flexible substrates. These displays, however, are complex laminates comprised of numerous materials with varying elasticities. So, though they can bend, they are not easily compressed and stretched. When a laminate is bent, there is a neutral bend axis where the material experiences neither a compression nor a tension stress. The material outside this axis experiences tension stresses while the material inside this axis experiences compression stresses. It is preferable for this neutral bend axis be reserved for the layer in the display least able to withstand these stresses.
It is often desirable for the display on a mobile device to be mounted to a case that can act as a base for the display and contain electronics, batteries, and the like. To be able to fold the device, the case will require a hinge. Traditional hinges contain the neutral bend axis, thus causing tension or compression stress in the display mounted to the case as the device is folded.